Confining and separating or otherwise manipulating ions with ion guides and/or ion traps is widely used in analytical techniques such as mass spectrometry (MS). Ion traps are also used for other applications such as quantum computing. Trapped ions can be used for accumulating a population of ions to be injected into an ion mobility drift cell to perform ion mobility spectrometry (IMS) to separate, identify, or distinguish ions or charged particles based on their size or collision cross section. IMS can be employed in a variety of applications such as separating structural isomers and resolving conformational features of charged chemical compounds, macromolecules, and essentially any charged particles. IMS may also be employed to augment mass spectroscopy in a broad range of applications, including metabolomics, glycomics, and proteomics, as well as for a broad range of applications involving essentially any compound that can be effectively ionized.
Radio Frequency (RF) fields are commonly utilized in ion traps and ion guides for ion confinement. RF voltages are typically applied 180° out of phase to effectively generate a pseudopotential that confines ions and prevents ions from approaching electrodes generating the RF fields. The axial motion of ions inside an ion guide can be produced by a DC gradient, a traveling wave, or a gas flow.